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Polymerization reactions in the thermal cracking of N‐substituted carbamates to produce the corresponding isocyanates significantly reduce the yield of isocyanates and thus vastly hinder the industrial application of such non‐phosgene routes. Herein, we tried to recycle the oligomers generated during the thermal cracking of 3‐ethylcarbamatopropyltriethoxysilane (CPTS) to produce 3‐isocyanatopropyltriethoxysilane (IPTS). Firstly, the polymerized substrates of the pyrolysis reaction were analyzed by NMR, IR, MALDI‐TOF‐MS and TG, indicating the pyrolysis substrates were mixtures of CPTS (25 wt%), polyureas (74 wt%), imines, and other compounds (<1 wt %). The polyureas were generated by reaction of CPTS and IPTS. Then, the depolymerization of these polyureas was realized via alcoholysis in the presence of urea. It was found that the urea not only provides a carbonyl group source, but also forms hydrogen bonds with polyureas. In addition, NH3 co‐produced can also modify the reaction system microenvironment, which might be favorable for the dissociation of polyureas. With optimized conditions, more than 96 % of polymerized substrates could be reverted to CPTS for secondary cracking. [ABSTRACT FROM AUTHOR]

New organic‐inorganic hybrid single lithium‐ion (Li+) conductors (SLICs) based on tetrazolate anion and −Si−O− species with polyethylene glycol (PEG) chains were developed using isocyanate as interim connection. The key design strategy is that the longer and freely movable wirelike PEG chain can improve Li+ transfer in the presence of a high charge delocalized tetrazolate anion, and the −Si−O− species might improve the interfacial stability at the Li anode. FTIR, solid‐state NMR, XPS, XRD, BET, TGA, and DSC experiments were performed and the electrochemical properties were tested. The chemical structure and basic physicochemical properties were confirmed and revealed preliminarily. At 30 °C, a high enough conductivity (3.3×10−6 S cm−1), Li+ transference number (0.86), and wide electrochemical window (4.5 V) were obtained from the pure SLIC based on PEG with molecular weight of 600 g mol−1. Besides, the developed SLICs displayed good interfacial compatibility with the Li metal electrode, as expected. [ABSTRACT FROM AUTHOR]

In this study, a green, efficient and low-cost process for the synthesis of N-methylpyrrolidine (NMPD) from 1,4-butanediol (BDO) and methylamine (MA) via a one-pot method was developed. Under the optimized reaction conditions, more than 90% yield of NMPD was achieved over a Cu and Ni modified ZSM-5 catalyst. The catalyst could be reused for several runs retaining a satisfactory catalytic performance, and the scale-up operation showed the potential of industrial application. Characterizations of BET, XPS, XRD, TEM, SEM, H2-TPR and NH3-TPD were conducted for the developed composite catalyst, which suggested that Cu2O and NiO were the main species on the support. Meanwhile, it was found that the H2 atmosphere, the high dispersion of metal oxides and the synergic effect between Cu and Ni species on ZSM-5 contributed to the excellent catalytic performance. Furthermore, a possible mechanism based on a borrowing-hydrogen process was also proposed. [ABSTRACT FROM AUTHOR]

A series of amino triazole alkali salts (MATriz, M was Li, Na, K) were prepared, characterized and used for the direct synthesis of polyureas from CO2 and diamines. Under the reaction conditions of an initial pressure of CO2 of 4 MPa, 170 °C, 8 h, good to excellent yields of various polyureas were achieved over the KATriz catalyst. According to the results of the characterization of the MATriz catalyst, it was found that the catalytic performance is essentially consistent with the basicity of salts. Besides, the catalyst could be easily recycled and reused for several runs without obvious deactivation. [ABSTRACT FROM AUTHOR]

A new basic catalyst 3-amino-1,2,4-triazole potassium (KATriz) was prepared, characterized and employed for synthesis of dimethylhexane 1,6-dicarbamate (MHDC) by methoxycarbonylation of 1,6-hexanediamine (HDA) and dimethyl carbonate (DMC). Results showed that KATriz exhibited high catalytic activity and selectivity, 100% HDA conversion with nearly 100% MHDC selectivity that could be obtained at room temperature. The catalyst can be reused for several runs without any deactivation. Besides, the influence of reaction conditions, the structure of amines and the possible catalytic mechanism were also investigated. [ABSTRACT FROM AUTHOR]

A composite oxide CuO–ZnO catalyst was prepared and tested in the degradation of various polyureas using urea as the carbonyl source for the first time in this field. Under the optimized reaction conditions, a 96% diethyl hexamethylenedicarbamate (EHDC) yield was obtained with polyurea-hexamethylenediamine (PU-HDA) over the CuO–ZnO catalyst. The characterization results of the structural and component properties of the prepared catalyst indicated that the Zn-rich polycrystalline oxide with good dispersion exhibited enhanced catalytic activity in this reaction system. Moreover, the catalytic mechanism of the CuO–ZnO catalyst in polyurea degradation was proposed and investigated preliminarily. [ABSTRACT FROM AUTHOR]

The catalytic activity of a cathode material plays a vital role in determining the electrochemical performance of Li–O2 batteries. Herein, N-doped mesoporous carbon-supported CoO@Co nanoparticles are prepared in situ using the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrachlorocobalt ([BMIm]2[CoCl4]) as the precursor with silica as the hard template. The material was characterized by TGA, BET, XRD, TEM, XPS, and H2-TPR. After exposure to air, the species on the surface of the Co is CoO, as verified by XPS. The pore size is about 2 nm, and the CoO@Co nanoparticles were irregularly shaped and sized in the range of 20–300 nm, which may have been due to the aggregation of ultrafine nanoparticles. The existence of an interaction between the CoO@Co nanoparticles and the N-doped support is confirmed by XPS and H2-TPR. The catalyst shows superior activity for oxygen evolution reaction (OER) manifested in its lower charge potential (3.75 V at the current density of 100 mA g−1). Enhanced performances in coulombic efficiency, rate capability, and cycling stability (55 cycles) are also realized. Finally, these improvements, with the exception of the catalytic activity of CoO, may benefit from the interaction between the carbon supporter and the CoO@Co nanoparticles. [ABSTRACT FROM AUTHOR]

Utilization of cheap and natural resources is an important topic in green chemistry. A new class of betaine-based aprotic task-specific ionic liquids (ILs), including [C4bet][TFSI], [C4bet][DCA], [C4bet][SCN], [1O2bet][TFSI], [1O2bet][DCA], [2O2bet][TFSI], and [2O2bet][DCA], has been designed and prepared through a new ionic liquidization strategy from the renewable natural resource betaine. Their physicochemical characteristics, including spectral properties, density, viscosity, melting point, glass transition temperature, thermal stability, conductivity and electrochemical window, have been comprehensively studied. They were first applied as new absorbents for SO2 capture, and [C4bet][SCN] exhibited the maximum absorption capacity of 0.93 molSO2/molILs at 20 °C and 1 atm (SO2/N2 = 10% vol.) with rapid absorption rates in 21 min. Moreover, the effect of temperature, pressure, and water content on the absorption performance of SO2 was investigated. The possible absorption mechanism was studied using FT-IR, NMR and quantum chemical calculation. In addition, the [C4bet][SCN] can maintain the high absorption capacity and the rapid absorption rates for 25 absorption/desorption cycles. [ABSTRACT FROM AUTHOR]

Correction for 'One-pot synthesis of N-methylpyrrolidine (NMPD) using Cu- and Ni-modified ZSM-5 as an efficient catalyst' by Yan Long et al., Green Chem., 2019, 21, 141–148. [ABSTRACT FROM AUTHOR]

Considering the significant influence of oxygen-containing groups on the surface of carbon involved electrodes, a carbon nanotube (CNT)-based MnO 2 composite catalyst was synthesized following a facile method while using polymerized ionic liquids (PIL) as sacrifice agent. Herein, the PIL (polymerized hydrophobic 1-vinyl-3-ethylimidazolium bis ((trifluoromethyl)sulfonyl)imide) wrapped CNTs were prepared. The composite was applied to support MnO 2 by the treatment of KMnO 4 solution, taking advantage of the reaction between PIL and KMnO 4 , which excludes or suppresses the oxidation of CNTs, and the as-synthesized material with fewer oxygen-containing groups acted as a cathode catalyst for Li-O 2 batteries, directly avoiding the application of binders. The catalyst shows enhanced activity compared to that of the samples without PIL, as verified by the lower overpotential during discharging and charging (0.97 V at the current density of 100 mA g -1 ). Meanwhile, the performance parameters such as Coulombic efficiency and rate capability were also improved for the Li-O 2 battery utilizing this catalyst. Further, the formation of confined Li 2 O 2 particles could be responsible for the reduction of charge potential of Li-O 2 batteries due to the synergy effect of the intrinsic catalytic activity of MnO 2 and fewer oxygen functional groups on the catalyst surface.